Update: We now build the amalgamation file with mingw and release the latest version of SQLite3, from this direct SQLite3-64.7z link, as soon as it is published on the SQLite3 site.
Up to now, there is no official Win64 version of the SQlite3
library released in http://sqlite.org..
It is in fact very difficult to find a ready-to-use and
up-to-date SQLite3-64.dll
from Internet, for Win64.
You can find the latest version of the SQlite3 external library, to be used in 64 bit mode, to be downloaded from SQLite3-64.7z.
It includes FTS3/FTS4/FTS5 virtual tables, and was compiled in release mode.
This is the version we use when our mORMot framework targets Win64, using latest versions of the Delphi compiler.